A term most commonly used by Stewie Griffin of Family Guy, a hit cartoon by Seth McFarlane.
If done correctly with accent and a good bit of exclamation, it can be an effective tool of mockery to be used after a victory, particularly a verbal showdown. If used after a physical encounter, you may have your ass kicked.
Person 1: stfu
Person 2: Perhaps if you can use full words, with at least one with more than one syllable, to insult someone, then perhaps, and that is only PERHAPS, I will be phased.
Person 1: *cries*
Person 2: Victory is mine!